All,
About a month ago a buddy of mine and I attempted to raise the blades onto the wind turbine at the top of my 70' freestanding tower. A number of technical glitches prohibited us from accomplishing this task. Believe me after that day I certainly had both 'tower envy' for those with tilting towers, and secretly wished that I had gone solar.
While I really like the aesthetics of the free standing tower, it provides me with challenges that those who have tilting towers never have.
Recently I completely rewired my tower (making it far better than original), put up a long Kellem wire grip onto my cables, made my davit crane better, added eye bolts on top to clip onto, replaced my C40 with a Tristar TS60, completed all wiring, among many other tasks.
Let's just say that I have become quite proficient at climbing my tower, and I understand a lot more now about inverter back-end systems than when started.
Up till recently I had to wait till the weekends to perform any work on the tower/turbine, but problems of weather/wind/logistics I have not been able to get the blades and tail up onto the turbine. It is always windy here and that along with the non-tilting tower have provided many obstacles.
Last Thursday the weather report finally was kind to me and we had next to perfect weather with only 3-4mph winds. So I took the opportunity to try to get things operational here.
First up were my blades and tail sections onto the turbine. The stator was shorted so that the rotors could be turned but would inhibit the blades from rotating. With the stator shorted you can turn the rotors, it does not turn easily but this gave me the ability to align the rotor to the holes on the hub.
Here is a picture with me threading the nuts onto the threaded rod that holds the blades onto the turbine. I used lock washers, lock tite, and double nutted each stud:
Once the blades were on the brake actuator was engaged to positively keep the blades from rotating, and the guide rope was removed.
Next up was the tail this was a little more difficult as the lift point was a little bit off on the tail. The lift point should be slightly off center and away from the tail vane so that it can be put onto the yaw bearing easily, my lift point was on the side towards the tail vane making it slightly difficult to maneuver. But eventually I was able to man-handle it and get it onto the pivot point.
The next picture shows that the lift point was too far out and was also a reach for the winch as well:
The crane worked very well and I am quite happy with how it performed.
Next comes Murphy's law again - the telescoping tower stub. When we connected the winch and attempted to lift the stub it would not move. As it started to lift I could see resistance from the lower mounting plate.
Last fall prior to having the crane lift the tower into position the stub was checked out to ensure that it could rotate in the mounting collars, if it can rotate, the it can be telescoped. I suspect that since the tower was lifted by the top mounting plate that the alignment of the collars got 'tweaked' a bit. I put a long bar through the pin hole and tried to rotate the stub, but it would not move.
Hind site being what it is I believe that I should have made the lower mounting plate with the collar separated - instead of welding them together. And then using some L's on the collar and bolted them through the top of the plate would have been the best solution. The mounting bolt holes could be slotted to allow the collar to be shifted and easier to get/keep aligned. Experience really does make a difference in these small design and construction details.
At this point I had been on the tower easily 4 hrs and was getting tired so decided to call it a day.
For now the blades and tail are lashed to the tower to keep it from rotating, as until I extend the top stub there is not clearance for the blades when the wind attempts to turn the turbine.
Here are a couple of pictures of the tower with the completed turbine, being that they were taken from downhill the tower appears taller than it actually is:
Tomorrow the weather forecast is favorable so I am hoping to remove the lower mounting plate, rework it, get it back up and extend the telescoping stub. We'll see if I can get it done in a day.
The last couple of days I have lucked out because the wind has come from basically the same direction, however it is forecasted that in 2 days a storm is blowing in from the south. If I can't complete the tasks then I may need to remove the tail.
To be continued...
Dan Lenox
